Differential-fill wound package



March 29, 1966 P. D. CHASTANG DIFFERENTIAL-FILL WOUND PACKAGE 2Sheets-Sheet 1 Filed Nov. 24, 1964 INVENTOR. PELHAM D. CHASTANG ATTORYMarch 29, 1966 Filed NOV. 24, 1964 P. D. CHASTANG 3,243,142

DIFFERENTIAL-FILL WOUND PACKAGE 2 Sheets-Sheet 2 (D LLI I 3- U E I; E 22- LL! 0 l O. U) 5 l CAM ANGLE 1 [KR AM A I i 1 l ,U W EI' FIG. 3.

INVENTOR. PELHAM D. CHASTANG ATTO EY Patented Mar. 29, 1966 3,243,142DIFFERENTIAL-FILL WOUND PACKAGE Pelham Dewey Chastang, Pensacola, Fla.,assignor to Monsanto Company, a corporation of Delaware Filed Nov. 24,1964, Ser. No. 413,573 4 Claims. (Cl. 242-178) This is acontinuation-in-part of my co-pending application S.N. 296,992, filedJuly 23, 1963, now abandoned.

The present invention relates to yarn winding method and apparatus forproducing differential-fill wound packages having straight barrel sidesand straight tapers.

In a conventional differential-fill wound (DFW) package, the yarn beingwound on a bobbin is cyclically traversed axially along the bobbin at asubstantially constant stroke length so that yarn is distributed over agiven area on the bobbin. Superimposed on this primary traversal is aslower cyclic axial traversal movement which gradually shifts the areain which the yarn is being built up back and forth along the bobbinaxis.

Ideally such a DFW package will have a straight barrel or right circularcylindrical central region, and a conical tapered region on each endtapering down from the barrel to the bobbin. Preferably, theintersections of the barrel with the conical end portions should berounded rather than meeting in a sharp shoulder. Such a DFW packageoffers several advantages over other types of yarn packages. Forexample, the package may be readily cleaned to eliminate surface soilingby stripping off the soiled surface yarn, a procedure which cannot beemployed with warp-wound or compound-fill wound packages. DFW packagesmay readily be made relatively free of barr effects. A furtheradvantage, where packages are being built on multi-position windingapparatus, is that random dofiing may be employed. That is, a particularposition may be defied and a new package started at any time withoutdisturbing the other positions and without making any adjustments to thewinding apparatus. This fea ture can become decidedly advantageous froman economic standpoint since it permits more effective and continuoususe of all positions.

The prior art attempts to produce DFW packages have not been completelysuccessful due to inherent disadvantages of the mechanisms employed.Typical mechanical builders were incapable of providing rapid reversalof the yarn at the end of a traverse. This permitted the yard to buildup in the vicinity of the traversals, and prevented production ofstraight conical end portions. It has been found that severe sluffing ofthe yarn can occur if the angle between the conical surface and thepackage axis is greater than about 30, and usually this occurs if theangle is greater than 24, but that slufling is substantially eliminatedif the angle is less than 24. Prior art builders which were designed tooperate within this limitation on the cone angle have heretofore beenunable to maintain a true conical surface. Typically the angle of thetapered surface was much larger at the outer extremity of the taperedregion due to the failure to provide sufficiently rapid reversal at thetraversal point.

Accordingly, a primary object of the invention is to provide windingapparatus for building differential-fill wound Packages.

A further object is to provide packages of the above character having astraight barrel central region and straight tapered end regions.

A further object is to provide packages of the above character whereinthe junctions between the barrel sides and the tapered regions are inthe form of rounded transitions.

A further object is to provide apparatus of the above character which isflexible and which permits ready control or adjustment.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others, and thearticle possessing the features, properties, and the relation ofelements, which are exemplified in the following detailed disclosure,and the scope of the invention will be indicated in the claims.

For a more complete understanding of the nature and objects of theinvention, reference should be made to the following detaileddescription taken in connection with the accompanying drawing, in which:

FIGURE 1 is a fragmentary perspective view of an exemplary embodiment ofthe invention,

FIGURE 2 is a graph of cam displacement vs. cam angle of the preferredcam in FIGURE 1, and

FIGURE 3 is a schematic view illustrating how the traverse patternproduced by the cam displacements of FIGURE 2 produces the desiredpackage profile.

Referring now to FIGURE 1, yarn 20 is fed at a con stant speed from asuitable source (not illustrated) to be wound on a rotating bobbin 22. Atraverse ring 24 surrounds bobbin 22, and is repeatedly traversedparallel to the axis of the bobbin by extension and retraction of piston26 on a double-acting hydraulic cylinder 28. A traveler 30, throughwhich yarn 20 is threaded, orbits on ring 24 to form therewith atraverse mechanism, as will be understood by those skilled in the art.The axial position along bobbin 22 where yarn 20 is placed is thusdetermined by the instantaneous position of ring 24.

The range of movement of piston 26, and thus of ring 24, is controlledby the illustrated preferred cam assembly. A cam shaft 32 is rotatablymounted adjacent and parallel to piston 26, and is rotated by a clockmechanism illustrated as motor 34 at a slow rate. Right circularcylindrical members 36 and 38 are rigidly mounted at axially spacedpositions on shaft 32, and are concentric with shaft 32. The opposedfaces ofmembers 36 and 38 are shaped to form cam surfaces 40 and 42,respectively. These cam surfaces are inclined with respect to the axisof shaft 32, and are to a first approximation defined by theintersections of parallel planes with members 36 and 38. However, aswill be explained, the cam surfaces advantageously differ slightly butsignificantly from those which would be produced by intersection ofmembers 36 and 38 by planes.

A cam-sensing assembly 44 controls the cyclic operation of piston 26 inaccordance with the rotation of shaft 32. Assembly 44 includes amounting plate 46 mounted for movement with ring 24. One end of acam-sensing finger 48 is pivotally mounted on plate 46 by pivot pin 50,the opposite end 52 extending between cam surfaces 40 and 42.Micro-switches 54 and 56 are mounted on plate 46 on opposite sides offinger 48 and have their plungers facing the finger, so that rotation offinger 48 upwardly about its pivot will actuate switch 54, whilerotation of finger 48 in the opposite direction will actuate switch 56.Finger 48 may be spring-loaded to the intermediate position illustratedif desired, although the plunger springs of the micro-switches may besufiiciently strong themselves to avoid the need for a separate spring.

Switches 54 and 56 are connected through cable 58 to control the flow ofhydraulic fiuid to cylinder 28 through a suitable solenoid diversionvalve 60, etc., so that upon actuation of switch 54, piston 26 is drivendown or retracted until switch 56 is actuated, whereupon piston 26 isdriven up until switch 54 is again actuated. This basic sequence ofoperations is cyclically repeated so that yarn is deposited on thebobbin in the area between the limits of travel of ring 24.

As piston 26 is extended from the position illustrated, ring 24 andassembly 44 will be raised until the end 52 of cam finger 48 engages thecam surface 40, closing switch 54. The points in the stroke of piston 26at which the piston reverses direction are thus determined by theangular position of shaft 32. By rotating shaft 32 so that onerevolution occupies considerably longer than the time required forpiston 26 to travel through one of its cycles, the area on bobbin 22upon which yarn is wound is gradually shifted up and down to form theyarn package having contours similar to those illustrated. As anexample, shaft 32 may be driven to rotate four times per hour, whilepiston 26 would complete a cycle every few seconds. This superimposes onthe basic sequence noted above a cyclic shifting of the limits of travelof ring 24, so that the package contours are controlled according to theshape of the cam surfaces.

As previously mentioned, cam surfaces 40 and 42 may advantageouslydiffer from those which would be produced by intersection of members 36and 38 by planes. In order to produce tapered regions which closelyconform to the desired conical configuration, the cam surfaces 40 and 42are preferably somewhat modified to conform to the exemplary cam curveas given by the following table and illustrated in FIGURE 2, wherein theaxial displacement of surface 42 relative to a fixed point on shaft 32is given in inches for various angular positions of shaft 32, startingat the portion of surface 42 which is furthest from motor 34.

TABLE I Displace- Displacement, inches ment, inches Angle, degreesAngle, degrees or 360 0. 000 100 or 2G0 1. 665 or 355 0. 117 110 or250 1. 789 or 350- 0.226 120 or 240 1. 909 or 345- 0. 334 130 or 230-2.027 or 340. 0. 433 140 or 220- 2.140 or 330 0. 622 150 or 210- 2. 253or 320 0. 797 160 or 200- 2. 362 or 310. 0. 958 165 or 195 2. 416 or300.- 1.130 170 or 190 2. 473 or 290 1 262 175 or 185 2. 539 or 280 1.398 180 or 180 2. 600 or 270 1. 536

Cam surface 40 is identical to surface 42 although oppositely disposedon shaft 32, so that the reference or zero point is the point nearestmotor 34. Cam surface 42 is thus rotated 180 with respect to cam surface40. The traversal limits are at their lowest extreme displacement whenthe cam-sensing assembly 44 responds to the 0 position of cam surface42, and are at their opposite and highest extreme displacement whenassembly 44 responds to the 180 position of cam surface 42. Thetraversal limits are thus gradually shifted back and forth betweensuccessive extreme displacements which occur at the 0 and 180 positionsof cam surface 42.

FIGURE 3 illustrates the relationship between the cam profile, thetraverse pattern, and the contours of the yarn package produced, showingthat the contours of the tapered region are controlled by the camprofile.

The angular displacements specified in Table I correspond to a fixedlength of yarn per degree so long as the yarn take-up speed and therotational speed of shaft 32 remain proportional to one another.Ordinarily these factors will remain constant during operation. Thus ata yarn take-up speed of 300 yards per minute, each 5 increment in TableI corresponds to 62.5 yards of yarn taken up, while each 10 incrementcorresponds to yards of yarn taken up.

Table I may be converted to define the relationship in terms of the yarnlengths L between various particular points on the yarn and a referencepoint on the yarn which was wound during the occurrence of and thuscorresponds to one of the outermost extreme displacements of thetraversal limits. This is set forth in Table II, wherein M representsthe length of of the yarn wound on the bobbin between successive extremedisplacements of the traversal limits, e.g., during 180 rotation ofshaft 32. Length M thus corresponds to the length of yarn wound onbobbin 22 during each 5 of rotation of shaft 32.

TABLE 11 Length L Displace- Length L Displacement, inches ment, inches0. 000 20 or 52M 1. 665 0. 117 22 or 50M 1. 789 0. 226 1. 909 0. 33-1 2.027 0. 433 2. 0. 622 2. 253 0. 797 2. 362 0. 958 2. 416 1. 130 2. 473 1.282 2. 539 1. 398 2. 600 18 or 54M 1. 536

In the disclosed apparatus, it may be seen on inspection that length Mis dependent solely upon the yarn takeup speed (e.g., the speed at whichyarn 20 is fed to bobbin 22) and upon the rate of revolution of shaft32, and is independent of the r.p.m. of bobbin 22 and of the speed ofpiston 26. In the specific embodiment noted above, M equals 62.5 yards.According to Table II, and selecting as the reference point one whichwas wound during an extreme downward displacement of the limits, wheneither M or 71M (62.5 or 4437.5, respectively) yards have been woundafter the reference point, the lower limit will be 0.117 inch above itslowest point, while the upper limit will be 0061 (2600-2539) inch aboveits lowest point. Similarly, when either 3M or 69M (187.5 or 4312.5,respectively) yards have been wound after the reference point, the lowerlimit will be 0.334 inch above its lowest point, while the upper limitwill be 0.184 (2.600- 2.416) inch above its lowest point. Since theupper and lower traverse limits are moved different distances for agiven rotation of shaft 32, the traverse stroke length actually variessomewhat for different angular positions of the cams.

The packages produced by cams formed according to the above Table I arecharacterized by having conically tapered end portions and a cylindricalcentral region, connected by a rounded intersection region to facilitateremoval of the yarn from the package.

It will be understood that the curve defined by Table I herein would beduplicated in substance if the displacements are substantiallyproportional to those given in the table. Thus if the displacement is,for example, 1.300 inches, the 90 displacement would be about 0.768 inchin a cam curve according to the present invention. The sameconsiderations of course apply to Table II.

The displacements of the traversal limits according to the presentinvention are not linear with respect to either time -or yarn length L,since it is desired to produce true conical surfaces. It may be seenthat a given length of yarn wound near an outer extremity'of a taperedend region will produce a greaterincrease in package diameter at thatpoint thanwillthe same length of yarn wound nearer the barrel, region,since the average change in package radius produced by adding a givenlength of yarn is inversely proportional to the square of the averagepackage radius on which the yarn is wound. Accordingly, lineardisplacement of the traversal limits will produce a convex end regionrather than a conical end region. Since the permissible angle of thetapered end surfaces with the bobbin axis is limited to 24 or less, asnoted above, provision of conical end regions permitsa maximum amount ofyarn to be wound on a package of a given maximum diameter. This isaccomplished by the present invention.

Many detail changes may be made in the specifically disclosed. apparatuswithout departing from the spirit of the invention. Thus, microswitches54 and 56 could be mounted on plate 46with their plungers in line withand facing the proper cam surface, so that finger 48 could beeliminated. Likewise the carnsurfaces and 42 could be reversed so as toface away from each other if the micro-switches were suitably mounted soas to be engaged at the proper points in the stroke of piston 26.

Other means, such as photosensitive devices, can 'be used to detect theedges of the cams and thus control cylinder 26. The micro-switches maybe replaced by a mechanically operated hydraulic diversion valve forcontrolling cylinder 28, if the diversion valve is moved with piston 26and physically located to be actuated by contact with cam surfaces 40and 42. While the preferred mechanism for traversing ring 24 is ahydraulic cylinder 28, other reversible linear motors may be substitutedtherefor. Ring 24 may be driven through a linkage such as a bell crank,rather than being directly attached to the piston of the linear motoremployed.

Similarly while only a single winding position is shown, it should beunderstood that in normal practice several traverse rings would bedriven by a single hydraulic cylinder and controlled by a single pair ofcams 40 and 42.

From the above description and the accompanying drawing it may be seenthat novel differential-fill wound packages having conical tapered endportions and a right circular cylindrical central region have beenprovided. Packages wound according to the disclosed cam configurationhave rounded transistion regions between each conical end portion andthe central region, thus facilitating smooth removal of the yarn fromthe package. The specific disclosed apparatus, including a pair ofopposed cams and a cam sensing mechanism for controlling the traversemechanism produces the desired DFW package in an efiicient manner,requiring a minimum number of auxiliary control parts since one cam andcam sensing assembly can control an entire bank of positions.

It will thus be seen that the objects set forth above; among those madeapparent from the preceding description, are efi-lciently attained and,since certain changes may be made in carrying out the above process, inthe described product, and in the constructions set forth withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A yarn package comprising in combination:

( a) a cylindrical bobbin,

(b) and yarn wound around the periphery of said bobbin to form apackage, said yarn repetitively traversing along the axis of saidbobbin, between:

(1) a first limit displaced substantially proportional to the.displaoementsdefined in.Table II, 5 wherein L represents the yarnlengths between specified points on said yarn and a reference point'onsaid yarn which corresponds to one of the outermost extremedisplacements of said limit, and wherein M represents of the lengthsecond limit being shifted 36M in respect to the instantaneousdisplacement value of said first limit. 2. The method of distributingyarn along. the axis of a rotating bobbin comprising the steps of:

said bobbin so that said yarn is deposited in an area between givenlimits along the axis of said bobbin,

(b) and simultaneously:

(1) as said yarn is wound on said bobbin, displacing a first of saidlimits substantially proportional tothe displacement-s defined in TableII wherein L represents the yarn lengths between specified points onsaid yarn and a reference point on said yarn which corresponds to one ofthe outermost extreme displacements of said limit, and wherein Mrepresents & of the length of the yarn wound on said bobbin betweensuccessive extreme displacements of said limit, as follows:

TABLE II Length L Displace- Length L Displacement, inches ment, inches0. 000 20 or 52M 1. 665 0.117 22 or 50M 1.789 0.225 24 or 48M 1.9090.334 26 or 4sM 2.027 0.433 23 or 44M 2.140 0. 022 30 or 42M 2. 253 0.797 32 or 40M 2. 362 0. 95s 33 or 39M 2. 410 1. 130 34 or 38M. 2. 473 1.252 35 or 37M 2.539 1.398 30 or 36M 2. 600 13 or 54M 1. 530

(2) and displacing the other of said limits substantially proportionalto the displacements defined in Table II, the instantaneous displacementvalue of the other of said limits being shifted 36M with respect to theinstantaneous displacement value of said first limit.

3. In yarn winding apparatus wherein a traverse mechanism distributesyarn along the .axis of a rotating bobbin, apparatus for controllingsaid traverse mechanism comprising in combination:

(a) a first cam surface having linear and angular dis- (a) repetitivelytraversing said yarn along the axis of i placements substantiallyproportional to those defined in Table I as follows:

displacements substantially proportional to those defined in Table I asfollows:

TABLE I TABLE I Angle, degrees Displace- Angle, degrees Displace- Angle,degrees Displace' Angle, degrees Displacement, inches ment, inches ment,inches ment, inches 0.000 100 or 260- 1. 665 Or 360 0.000 or 260- 1. 6650. 117 or 250. 1. 789 0. 117 110 or 250 1. 789 O. 226 120 or 240 1. 9090. 226 120 or 240. 1. 909 0. 334 or 230 2.027 0. 334 130 or 230 2.027 0.433 or 220 2. 140 0. 433 140 or 220- 2. 140 0. 622 or 210 2. 253 O. 622150 or 210. 2. 253 O. 797 or 200- 2. 362 0. 797 160 or 200. 27 362 0.958 or 195- 2. 416 0. 958 165 or 195 2. 416 1. 130 or 190- 2. 473 1. 130170 or 190. 2. 473 1. 262 or 185- 2. 539 1. 262 175 or 185 2. 539 1.398or 180 2. 600 1. 398 180 or 180- 2.600 1. 536 1. 536

(b) a second cam surface substantially identical to said first camsurface and having linear and angular displacements which are 180angularly displaced from those specified in Table I,

(c) reversible drive means for driving said traverse mechanism parallelto the axis of said bobbin,

(d) cam surface sensing means attached to said traverse mechanism andpositioned between said cam surfaces for reversing the direction ofmovement of said drive means when said cam surfaces are detected by saidsensing means,

(e) and drive means for synchronously driving said cam surfaces at a lowrate as compared to the traversal rate.

4. In yarn winding apparatus wherein a traverse mechanism distributesyarn along the axis of a rotating bobbin, apparatus for controlling saidtraverse mechanism, comprising in combination:

(a) a hydraulic cylinder having its .piston attached to said traversemechanism whereby said traverse mechanism may be traversed axially alongsaid bobbin,

(b) and means for so controlling said piston that said yarn is wound onsaid bobbin in the form of a package, said control means comprising:

(l) a first cam surface having linear and angular a second cam surfacesubstantially identical to said first carn surface and having linear andangular displacements which are 180 angularly displaced from thosespecified in Table I,

cam surface sensing means attached to said traverse mechanism andpositioned between said cam surfaces for reversing the direction ofmovement of said drive means when said cam surfaces are detected by saidsensing means,

and drive means for synchronously driving said cam surfaces at a lowrate as compared to the traversal rate.

References Cited by the Examiner FOREIGN PATENTS 11/1930 Great Britain.

STANLEY N. GILREATH, Primary Examiner.

MERVIN ST-EIN, Examiner.

1. A YARN PACKAGE COMPRISING IN COMBINATION: (A) A CYLINDRICAL BOBBIN,(B) AND YARN WOUND AROUND THE PERIPHERY OF SAID BOBBIN TO FORM APACKAGE, SAID YARN REPETITIVELY TRAVERSING ALONG THE AXIS OF SAIDBOBBIN, BETWEEN: (1) A FIRST LIMIT DISPLACED SUBSTANTIALLY PROPORTIONALTO THE DISPLACEMENTS DEFINED IN TABLE II, WHEREIN L REPRESENTS THE YARNLENGTHS BETWEEN SPECIFIED POINTS ON SAID YARN AND A REFERENCE POINT ONSAID YARN WHICH CORRESPONDS TO ONE OF THE OUTERMOST EXTREMEDISPLACEMENTS OF SAID LIMIT, AND WHEREIN M REPRESENTS 1/36 OF THE LENGTHOF THE YARN WOUND ON SAID BOBBIN BETWEEN SUCCESSIVE EXTREMEDISPLACEMENTS OF SAID LIMIT, AS FOLLOWS: